Slim vermiculite board for construction finishing

ABSTRACT

The present invention relates to a slim vermiculite board for construction finishing comprising, to 100 parts by weight of fired vermiculite, 2.5-3.5 parts by weight of an additive and 100-120 parts by weight of a binder. The slim vermiculite board can help create a beautiful and luxurious interior by means of products having the natural patterns and diverse colors of vermiculite, does not produce construction waste and can be used as an agricultural soil conditioner. Also, the slim vermiculite board is light and easy to install, does not cause efflorescence, is deformation-free and eco-friendly, and has excellent deodorizing, antibacterial and fire-resistant properties and an excellent sound absorption coefficient.

TECHNICAL FIELD

The present invention relates to a slim vermiculite board for construction finishing. More particularly, the present invention relates to a slim vermiculite board for construction finishing which is prepared using liquid potassium silicate, as a binder, to provide good flowability and thus provide satisfactory mixing and does not exhibit efflorescence, a molding time of which may be minimally shortened due to easy addition in a predetermined amount during molding to be massively produced, and which has increased strength and a minimized deformation rate.

BACKGROUND ART

Since vermiculite emits far infrared light which is beneficial to the human body, and has excellent deodorization effect, antibacterial effect, and fire resistance, it is widely used in materials for construction, ceilings of motorcars and trains, wall materials, electronic materials, and the like and is added in powder form to nonflammable paints, coatings, fillers, and the like.

In particular, vermiculite has a characteristic of expanding when it is fired at high temperature. Since such expanded vermiculite has low density and exhibits excellent deodorization effect, antibacterial effect, and fire resistance, it can be manufactured into a board (plate) shape and is being used as an interior or exterior material for construction.

Although vermiculite has various advantages, particle sizes thereof are not uniform, and it is a mineral having many pores with non-uniform sizes and very high deformation. Accordingly, vermiculite has no adhesive force (cohesive force), thereby being manufactured into a vermiculite board using a binder.

Korean Patent No. 10-0695910 (registered on Mar. 20, 2007) discloses a vermiculite board including 100 parts by weight of expanded vermiculite, 50 to 90 parts by weight of an organic binder which includes 70 to 90% by weight of an epoxy resin and 10 to 30% by weight of a phenolic resin, and 1 to 10 parts by weight of clay.

Although the vermiculite board has high strength, the organic binder generates severe exhaust (toxic gas) when it is burned.

Korean Patent No. 10-0760149 (Sep. 18, 2007) discloses an interior material for construction manufactured by mixing and stirring formed stone, which is produced by foam-molding vermiculite, with sodium silicate, and then compression-molding and drying the same.

Although the constructional interior material has excellent flammability, sodium silicate, as a binder, has poor flowability. Accordingly, it is difficult to accomplish uniform mixing, whereby the mixture is partially agglomerated and becomes lumpy. In addition, since the mixture is very sticky, it is difficult to feed the same into a mold in a predetermined amount and, accordingly, it takes long time to produce the constructional interior material.

RELATED ART DOCUMENTS Patent Documents

(Patent Document 1) KR 10-0695910 B1 2007 Mar. 20.

(Patent Document 2) KR 10-0760149 B1 2007 Sep. 18.

DISCLOSURE Technical Problem

Therefore, the present invention has been made in view of the above problems, and it is one object of the present invention to provide a slim vermiculite board for construction finishing which is prepared using liquid potassium silicate, as a binder, to provide good flowability and thus provide satisfactory mixing and does not exhibit efflorescence, a molding time of which may be minimally shortened due to easy addition in a predetermined amount during molding to be massively produced, and which has increased strength and a minimized deformation rate.

Technical Solution

In accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of a slim vermiculite board for construction finishing, including 2.5 to 3.5 parts by weight of an additive and 100 to 120 parts by weight of a binder based on 100 parts by weight of fired vermiculite, wherein the additive is titanium dioxide.

The fired vermiculite is produced by firing vermiculite at 1,000 to 1,100° C.

The binder is liquid potassium silicate.

The liquid potassium silicate has a specific gravity (20° C.) of 1.381 to 1.394, a molar ratio of SiO₂ to K₂O is 3.15 to 3.35, and the liquid potassium silicate has a viscosity of 0.7 to 0.9 cps at 20° C.

The liquid potassium silicate includes 11.5% by weight of K₂O and 24% by weight of SiO₂.

The liquid potassium silicate maintains temperatures of 25 to 30° C. and humidity of 54 to 56%.

Advantageous Effects

As apparent from the fore-going, the present invention advantageously provides a slim vermiculite board for construction finishing which has natural vermiculite patterns and various colors, and thus, can help create a beautiful and luxurious interior. In addition, the slim vermiculite board does not produce construction waste, can be used as an agricultural soil conditioner, and is light.

Further, the slim vermiculite board is deformation-free, eco-friendly, and advantageously has excellent deodorization effect, antibacterial effect, fire resistance, and sound absorption coefficient.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram illustrating a process of continuously mixing raw materials, such as vermiculite, titanium dioxide, and a binder, using a raw material mixer equipped with an apparatus for producing a vermiculite board and a process of storing the resultant mixture using a storage equipped with the apparatus.

FIG. 2 is a schematic diagram illustrating a molding apparatus for molding a vermiculite board using the final mixture mixed by means of the raw material mixer illustrated in FIG. 1.

FIG. 3 is a series of process flowcharts illustrating a method of manufacturing a vermiculite board.

FIG. 4 illustrates photographs of a slim vermiculite board for construction finishing manufactured by variously processing a surface of a vermiculite board manufactured according to Example 1.

FIG. 5 illustrates photographs of a vermiculite board manufactured according to Comparative Example 1.

FIG. 6 illustrates a test report on moisture content, flexural failure load, and thermal resistance of a vermiculite board manufactured according to Example 1.

FIGS. 7 and 8 illustrate test reports on a sound absorption coefficient of a vermiculite board manufactured according to Example 1.

FIGS. 9 and 10 illustrate reports on an incombustibility test and a gas hazard test of a vermiculite board manufactured according to Example 1.

FIGS. 11 and 12 illustrate a heavy metal presence test report and a harmful substance presence test report on a vermiculite board manufactured according to Example 1.

FIG. 13 illustrates a report on a total volatile organic compound presence test, a toluene presence test, and a formaldehyde presence test of a vermiculite board manufactured according to Example 1.

FIG. 14 illustrates a report on a far-infrared radiation rate test and a far-infrared radiation energy test of a vermiculite board manufactured according to Example 1.

FIG. 15 illustrates a radioactivity index test report on a vermiculite board manufactured according to Example 1.

BEST MODE

Hereinafter, the present invention is described in detail.

Conventional vermiculite boards produced using vermiculite, as a main material, have generally been used as an industrial insulator or core material.

Conventional vermiculite boards exhibit efflorescence and collapse due to deformation, when exposed to water or air. Accordingly, vermiculite boards have not been used as finishing materials for construction.

In the case of conventional finishing materials for construction, pearlite is used as a main material and vermiculite is included in an amount of 30% or less therein.

The present invention is advantageous in that, although pearlite is not used and vermiculite is only used as a finishing material for construction, deliquescence is improved, efflorescence is not exhibited, and a vermiculite board is not deformed.

First, the slim vermiculite board for construction finishing according to the present invention is described in detail.

The slim vermiculite board for construction finishing of the present invention preferably includes 2.5 to 3.5 parts by weight of an additive and 100 to 120 parts by weight of a binder based on 100 parts by weight of fired vermiculite.

The fired vermiculite is preferably fired at 1,000 to 1,100° C. When the fired vermiculite is fired at less than 1,000° C., vermiculite incompletely fired is partially present, whereby the weight increases, absorption performance is decreased, and color is non-uniform. When the fired vermiculite is fired at greater than 1,100° C., particles are crumbled, and powder is blown and aggregates into clumps when blended.

The additive is preferably included in an amount of 2.5 to 3.5 parts by weight based on 100 parts by weight of the fired vermiculite. When the additive is included in an amount of 2.5 parts by weight, cohesive force is decreased, whereby strength is decreased. When the additive is included in an amount of greater than 3.5 parts by weight, strength is slightly improved, but clumps are generated and powder blocks pores when blended, whereby absorption performance is decreased.

The additive is preferably titanium dioxide, but the present invention is not limited thereto.

Titanium dioxide has a high brightness, is satisfactorily mixed with a mixture, and increases strength.

The present invention is characterized in that titanium dioxide is inserted between pores of fired vermiculite so that cohesive force (adhesiveness) is increased and uniform pore state is maintained.

The present invention is characterized in that liquid potassium silicate (potassium silicate solution) is used as the binder.

When liquid sodium silicate is used as a binder, flowability is poor and thus it is difficult to accomplish uniform blending. Accordingly, partial aggregation occurs and clumps are generated. In addition, a mixture is very sticky, whereby it is difficult to feed the mixture in a predetermined amount into a mold, which causes long production time.

Since the present invention uses liquid potassium silicate as a binder, a mixture having a smooth surface and a viscous inside is generated, easy blending is accomplished due to good flowability, and efflorescence is not exhibited. In addition, the mixture may be easily fed in a predetermined amount during molding, whereby a molding time may be minimally shortened, which makes mass production possible. Further, strength is improved and deformation rate is minimized.

The present invention is characterized in that the specific gravity of liquid potassium silicate, a molar ratio of SiO₂ to K₂O therein, and the viscosity thereof are adjusted, thereby producing an optimal a binder for a vermiculite board.

In the present invention, liquid potassium silicate preferably has a pH of 11 to 12 and a specific gravity (20° C.) of 1.381 to 1.394, a molar ratio of SiO₂ to K₂O therein is preferably 3.15 to 3.35, and the viscosity thereof at 20° C. is preferably 0.7 to 0.9 cps.

According to the present invention, liquid potassium silicate preferably has a specific gravity (20° C.) of 1.381 to 1.394. When the specific gravity (20° C.) is less than 1.381, adhesive force is decreased, whereby strength is decreased. When the specific gravity (20° C.) is greater than 1.394, the binder becomes sticky, whereby it is difficult to perform blending and molding.

A molar ratio of liquid potassium silicate is calculated according to the following equation: Molar ratio of potassium silicate=Weight ratio of SiO₂/K₂O×1.568

In the liquid potassium silicate according to the present invention, a molar ratio of SiO₂ to K₂O is preferably 3.15 to 3.35. When a molar ratio of SiO₂ to K₂O is less than 3.15, heat resistance slightly increases, but adhesive force is decreased. When a molar ratio of SiO₂ to K₂O is greater than 3.35, adhesive force is improved due to increased viscosity, but a binder becomes sticky. Accordingly, it is difficult to perform blending and molding.

Liquid potassium silicate according to the present invention more preferably includes 11.5% by weight of K₂O and 24% by weight of SiO₂.

The liquid potassium silicate according to the present invention preferably has a viscosity of 0.7 to 0.9 cps at 20° C. When the viscosity thereof at 20° C. is less than 0.7 cps, it is easy to perform blending due to good flowability, but strength is deteriorated due to decreased adhesive force. When the viscosity thereof at 20° C. is greater than 0.9 cps, adhesive force is improved, but a binder becomes sticky. Accordingly, it is difficult to perform blending and molding.

The liquid potassium silicate is preferably maintained at temperatures of 25 to 30° C. and humidity of 54 to 56% which are most suitable conditions to exhibit the properties of vermiculite.

The binder is preferably included in an amount of 100 to 120 parts by weight based on 100 parts by weight of the fired vermiculite. When the binder is included in an amount of less than 100 parts by weight, adhesive force is remarkably decreased and heat resistance is deteriorated. When the binder is included in an amount of greater than 120 parts by weight, the weight and the viscosity increase, whereby it is difficult to perform molding.

The present inventors have filed an application for “Apparatus for manufacturing vermiculite board and method of manufacturing the same,” and this application has been registered (Korean Patent No. 10-1132034, Apr. 2, 2012).

FIG. 1 is a schematic diagram illustrating a process of continuously mixing raw materials, such as vermiculite, titanium dioxide, and a binder, using a raw material mixer equipped with an apparatus for producing a vermiculite board and a process of storing the resultant mixture using a storage equipped with the apparatus.

FIG. 2 is a schematic diagram illustrating a molding apparatus for molding a vermiculite board using the final mixture mixed by means of the raw material mixer illustrated in FIG. 1.

FIG. 3 is a series of process flowcharts illustrating a method of manufacturing a vermiculite board.

The application, entitled “Apparatus for manufacturing vermiculite board and method of manufacturing the same” (Korean Patent No. 10-1132034), which has been previously filed by the present inventors is characterized in that a binder in a mixture is not aggregated while uniformly mixing vermiculite and the binder in a continuous mixing process, so that the mixture may be fed in a predetermined amount into a press and a vermiculite board may be manufactured though a single press process at room temperature, which allows uniform quality obtainment and facilitates mass production.

The vermiculite board of the present invention is manufactured using the apparatus for manufacturing a vermiculite board and the method of manufacturing the same disclosed in the previous application (Korean Patent No. 10-1132034). Accordingly, detailed descriptions of the apparatus and the method are omitted.

Hereinafter, the constitution and functions of the present invention are described in more detail with reference to examples of the present invention. However, the following examples are merely provided as preferred embodiments and, therefore, the present invention is not limited to the examples.

Example 1

Vermiculite was fired at 1,000° C., thereby producing fired vermiculite. 3 parts by weight of titanium dioxide were fed into a first mixer containing 100 parts by weight of the fired vermiculite. The mixture including vermiculite and titanium dioxide was discharged and supplied to a second mixer by a first transfer screw (S10). Next, liquid potassium silicate with a humidity of 55% at 27° C. was supplied to the mixture of vermiculite and titanium dioxide which had been supplied to the second mixer. Here, high-pressure air was sprayed to the liquid potassium silicate in a direction perpendicular to a feeding direction of the liquid potassium silicate such that the liquid potassium silicate was dispersed and supplied in a small particle form without aggregation (S20). The liquid potassium silicate was used in an amount of 100 parts by weight based on 100 parts by weight of the fired vermiculite. The liquid potassium silicate was produced to have a specific gravity (20° C.) of 1.390, a molar ratio of SiO₂ to K₂O of 3.25, and a viscosity of 0.8 cps at 20° C. Here, since the second mixer was a transfer screw-type mixer, the liquid potassium silicate was continuously supplied in a constant amount to the mixture of vermiculite and titanium dioxide continuously flowing through the transfer screw. Next, a final mixture including vermiculite, titanium dioxide, and liquid potassium silicate discharged from the second mixer was introduced into a blowing fan assembly and pumped into a storage via a corrugator by flowing force of the blowing fan. Here, the final mixture was first collided with the blowing fan, and then secondarily collided with a corrugated part of the corrugator, whereby a binder gathered in a wing shape was finally dispersed into small particles, resulting in uniform mixing (S30). Next, the final mixture stored in the storage was pressed using a press, thereby molding a compressed vermiculite board (S40). More particularly, a molding frame of the press was filled with the final mixture through a hose lengthily extended from a discharge pipe of the storage (S41). Next, in the state in which the molding frame of the press was filled with the final mixture, an upper movable mold was lowered to press the final mixture, whereby the final mixture was compression-molded and thus a plate-type vermiculite board was produced (S42). Subsequently, when the vermiculite board was elevated to an upper part of the molding frame (S44) while a lifter plate of a fixed lower mold constituting a bottom of the molding frame was elevated by the operation of a lifting cylinder (S43), the vermiculite board was discharged to the outside of the press by an ejector plate through advancing operation of a cylinder rod of an ejector (S45, S46). Next, the vermiculite board discharged to the outside of the press was stacked on a lifter disposed at one side of the press. Here, since the height of the lifter was adjustable, a plurality of vermiculite boards was stacked while adjusting the height of the lifter according to the height of the vermiculite board discharged from the press and the height of the vermiculite boards stacked on the lifter (S50). Next, when a plurality of vermiculite boards was stacked on the lifter, the vermiculite boards were transferred to a first dryer, and each of the vermiculite boards was placed on a drying plate of the first dryer and was naturally dried for a predetermined time (S60). Finally, the vermiculite board naturally dried in the first dryer was transferred to a second dryer and was subjected to hot air drying for a predetermined time, thereby manufacturing a final vermiculite board product (S70).

Photographs of a slim vermiculite board for construction finishing manufactured by variously molding a surface of a vermiculite board produced as described above are illustrated in FIG. 4.

Comparative Example 1

50 parts by weight of a binder were mixed with 100 parts by weight of a mixture including 70% by weight of pearlite and 30% by weight of vermiculite, thereby manufacturing a vermiculite board. Photographs of the vermiculite board are illustrated in FIG. 5. Here, liquid sodium silicate was used as a binder.

Experimental Example 1

The properties of the vermiculite board manufactured according to Example 1 and the vermiculite board manufactured according to Comparative Example 1 are summarized in Table 1.

TABLE 1 Classifica- Comparative Characteristics tion Example 1 Example 1 of Example 1 Firing 1,150° C. 1,000° C. temperature Properties Hard Soft Upon Broken Not broken compression (pressed trail) Post- Necessary Unnecessary processing (coating, grinding, etc.) Pattern/ plane Various Product having natural design vermiculite pattern and various colors is manufactured. Accordingly, it is possible to create a beautiful and luxurious interior. Adhesive Efflores- No cence efflorescence Impact Weak Strong resistance Carrying/ Broken Transfer is transfer easy. Loss rate 40% or more About 1% Recycla- Impossible Possible Useable as an bility agricultural soil conditioner without generation of construction waste Process- Insufficient Excellent ability (no manual (manually operation) cuttable) Construct- Construction Easy Light and easily worked ability equipment construction with general tool such used as saw, knife, screw, or nail. Workability is excellent. Color Partially Can be possible colored Rainy season Swollen in Three months (exposure to short time or more water) Density Low density Adjustable to high density Mold Attached Not attached process- (residues are ability removable by air injection) Skin contact Hot in Not hot in 100% natural mineral that property contact with contact with is not harmful to human skin skin body and environment Heat Weak Strong resistance Molding Efflores- Satisfactory state cence frequently occurs

The slim vermiculite board according to Example 1 has natural vermiculite patterns and various colors and thus can help create a beautiful and luxurious interior, compared to the slim vermiculite board according to Comparative Example 1. In addition, the slim vermiculite board according to Example 1 does not produce construction waste, can be used as an agricultural soil conditioner, and is light.

Experimental Example 2

The performance of the vermiculite board manufactured according to Example 1 was evaluated and summarized in Table 2. A report on moisture content, flexural failure load, and thermal resistance tests is illustrated in FIG. 6, reports on a sound absorption coefficient test are illustrated in FIGS. 7 and 8, reports on incombustibility and gas hazard tests are illustrated in FIGS. 9 and 10, reports on heavy metal and harmful substance presence tests are illustrated in FIGS. 11 and 12, a report on total volatile organic compounds, toluene, and formaldehyde presence tests are illustrated in FIG. 13, a report on far-infrared radiation rate and far-infrared radiation energy tests is illustrated in FIG. 14, and a report on a radioactivity index test is illustrated in FIG. 15.

TABLE 2 Evaluation items Evaluation methods Criteria Performance Report No. Moisture content (%) KS L 9105:20009 3.0 or less 0.5 CTS13-72286 Flexural failure load (N) 40 or more 68 Thermal resistance (m² · K)/W 0.28 or more 0.12 Noise reduction coefficient (NRC) KS F 0.41 to 0.60 0.50 CT13-72294 2805:2004ASTM C 423:2009a Incombustibility test, mass KD FISO 9:00 or more 13:34 CT13-72278 reduction rate (%) 1182:2004 Incombustibility test, difference Should not 1.4 between peak temperature and final exceed 20 equilibrium temperature (° C.) Gas hazard test average, KS F 2271:2006 30 or less 6.9 deed stopping time (min:s) Lead (mg/l) Waste process Less than 3 Undetected CT13-72248 Hexavalent chromium (mg/l) test standard Less than 1.5 Undetected (Ministry of the Environment Copper (mg/l) Notice No. Less than 3 0.056 Cadmium (mg/l) 2001-160) Less than 0.3 Undetected Arsenic (mg/l) Less than 1.5 Undetected Mercury (mg/l) Less than 0.005 Undetected Cyanogen (mg/l) Less than 1 Undetected Organophosphorus (EPN) (mg/l) Less than 1 Undetected Organophosphorus (parathion) (mg/l) Less than 1 Undetected Organophosphorus (methyl dimethone) Less than 1 Undetected (mg/l) Organophosphorus (diazinon) (mg/l) Less than 1 Undetected Organophosphorus (pentoate) (mg/l) Less than 1 Undetected Trichlorethylene (mg/l) Less than 0.3 Undetected Tetrachlorethylene (mg/l) Less than 0.1 Undetected Oil component (%) Less than 5 Undetected Asbestos containment KS L 5300 Less than 1 Undetected Total volatile organic compounds Indoor air 0.4 or less 0.045 CT13-72260 (TVOC) (mg/(m² · h)) quality process Toluene (mg/(m² · h)) test standard 0.080 or less 0.002 Formaldehyde (mg/(m² · h)) (Ministry of 0.120 or less 0.002 Environment Notice No. 2010-24) Far-infrared radiation rate KCL-FIF- — 0.909 CT13-66163 1005:2011 Far-infrared radiation energy — 3.67 × 10² (W/m²) Radioactivity index HASL-300 1.0 or less 0.53187 CT-RM-13-0283 Ga-01-R:1997

As shown in Table 2, it can be confirmed that the vermiculite board according to the present invention is deformation-free and eco-friendly and exhibits excellent deodorization effect, antibacterial effect, fire resistance, and sound absorption coefficient. 

The invention claimed is:
 1. A slim vermiculite board for construction finishing, comprising 2.5 to 3.5 parts by weight of an additive and 100 to 120 parts by weight of a liquid potassium silicate binder based on 100 parts by weight of fired vermiculite, wherein the fired vermiculite is produced by firing vermiculite at 1,000 to 1,100° C., the additive is titanium dioxide, the binder has a specific gravity (20° C.) of 1.381 to 1.394, a molar ratio of SiO₂ to K₂O is 3.15 to 3.35, and has a viscosity of 0.7 to 0.9 cps at 20° C.
 2. The slim vermiculite board according to claim 1, wherein the liquid potassium silicate comprises 11.5% by weight of K₂O and 24% by weight of SiO₂. 